Looper-operating mechanism for sewing machines



Dec. 28 .1926.

A. B. CLAYTON LOOPER OPERATING MECHANISM FOR SEWING MACHINES Filed Dec. 7. 1922 u Il HIM-{MUNI- j wnNEssEs:

2 .Sheets-She'et 1 ATTORNEY Dec. 28 1926. 1,611,888

' A. B. CLAYTON LooPER OPERATING NEcHANIsM FOR sEwINe MACHINES Filed Dec. 1922 I 2 sheets-sheet 2 INVENTOR j w @www l BYY Patented Dee. 28, 1926.

Niren STATES hlt,

PAT-NT #if ANDREW B. CLAYTON, OF UNION, NEW JERSEY, .ASSIGNOR 'IO II-IE SINGER [tl.l!Cl\lU-'1 FACTURING UOMPANY, ELIZABETH, NEW JERSEY, A CORPORATION OF NEVT JERSEY.

LOOPER-OPERATING IVIECHANSM FOR SEWING MACHINES.

Application led December 7, 1922.l Serial No. 605,352.

This invention relates to sewing machines, more particularly of the singlesthread chainstitch type having an oscilla-ting loop-taker or looper, and has for an object to provide a loop-taker operating mechanism of simple construction whereby a slightly increased dwell is given to the loop-taker prior to the beginning of its loop-seizing movement, to give the needle time to throW out a needleloop large enough for certain seizure by the loop-taker. In machines of the singlethread chain-stitch type it is desirable t-hat the needle-loop be shed from the looper as quickly as possible after such loop has been entered by the descending needle, so that the remaining portion of the down-stroke of the needle Will be. sufficient to tighten the shed needle-loop, and a further object ot the invention is not only to slightly delay the beginning of the advancing movement of the looper, to give the needle added time to throw out a loop, but also to accelerate the latter portion of the retracting motion ot the looper to hasten the shedding of the needle-loop after the needle enters it.

Another object of the invention is to interconnect the needle and loop-taker so that they Will cooperate in accurately timed relation Without danger of such relation being lost by slippage or Wear of moving parts.

To the attainment oi tha ends in view, the loop-taker shaft is connected to be actuated by a guideway and follower connection with the vertical needle operating pitmanin the bracket-arm standard. The guidevvay is preferably displaced at a slight angle from a line normal or at right angles to the longitudinal axis of the pit-man, the angle of displacement from the normal line being preferably in the same direction as the direction of rotation of the main-shaft which actuates the pitman. This disposition of the guide- Way causes the looptaler to dwell slightly as the needle starts to rise and thus gives the needle an opportunity to throw out a larger loop and insures certainty of seizure of such loop by the loop-taker. This result is accomplished by the present mechanism While maintaining a minimum distance from the point of the loop-taker to the needleatthe beginning of the loop-seizing movement of the loop-taker, which condition permits of a minimum descent of the needle below the Work and a maximum time that the needle is out of the vvork at which time the feed must be accomplished.

In the accompanying drawings, Fig. l is a side elevation of a sewing machine embodying the invention. Fig. 2 is a horizontal section through the bracket-arm standard oi the machine showing the bed in plan. Fig. 3 is a vertical section tlrroughf the standard showing the loop-taker or looperactuating mechanism at the period of the cycle when the looper is at the end of its loop-seizing stroke and the needle is at its highest point. F 4. is a lvievv of the needle and looper in their respective positions corresponding to the positions of the parts in Fig. 3. Fig. 5 is a view similar to Fig. 3

but at the period in the cycle When the needle is at the end of its down stroke and the looper fully retracted. Fig. 6 is a view of the. needle and looper in their respective positions corresponding to the positions ot' the parts in Fig 5, and Fig. 7 is a cross section through the looper actuating guide- Way on the neeclle-baioperating pitman.

For the purposes of the present disclosure the invention is embodied in a single-thread chain-stitch serving machine having a frame casting formed With a bed l, standard 2, and overhanging bracket-arm 3 terminating in the head fl in Which is journaled the pressern bar 5 and reciprocating needle-bar 6 carrying the eye-pointed needle 7 which recipro, Cates as usual through the needle-hole in the throat-plate 8. Journaled in suitable bearings belowV the level of the throat-plate 8 is the main-shaft 9 carrying a spherical eccentric 10 which isembraced by the lovver strapped end of a pitman 1l disposed vertically within the standard EZ and connected at its upper end by means of a ballandsocket joint l2 to the rearward end of the needle-lever 13. The needle-lever 13 is ulf crumed at 14 on the braclet-arm 3 and at its forward end is connected by means oi the usual link 15 to the bracket 16 iixedto the needle-bar 6.

In the particular machine chosen 'for the purposes of the present disclosure, the looptaker 16 Which cooperates with the needle T is of the jt-Wo-.motion noir-th-read-carrying type common to single-thread chain-stitch machines, This loop-taker or looper is mountedon a looper-shaft 17 parallel to the main-shaft 9 and having collars 17 thereon to tix it against endwise movement. The loopershaft 17 has fixed to its rear end a .crank 18 which is connected by the link 19 'to one arm 2O of the bellcrankdever 20, 2l, fulcrumed on a. pin 22 fixed in the standard 2.

rl`he arm 2l ofthe bellcranl-lever has fixed in its free end a pin S23 having a reduced extremity d, Fig. T, entering an apertured slide-blocsA 25 cylindrically surfaced at 26, 26, toV tit the cylindricall), sn 'iced guideway 27 in the block 2S mom'ited on the pitman ll. intermediate the ends of the latter. The pin n i nl is located at level between the upper and lower cxtreme positions ot' the guideway 27.

The guideway 27 is preferably not disposed truly at right angles to the longitudinal arise- Fig. 5, of the pitman il but is inclined a little, say 5 or l0 decrees away from a line n., normal to the axis c-, the guidevvay 2.7 being preferably shifted or turned away from the normalrline n in the same direction in which the sl aft 9 rotates, i. e., counter-clockwise, as indicated by the arrows in Fig. The effect of this inclination of the guideway ZT is to cause the bellcranh 20, 2l and looper-actuating connection to dwell in the positions shown in 1Eig-s. 5 and 6 while the pitman l1 moves from full line to dotted line position, Fig, 5, thus lowering the upper end of the pitman 1l, a slight distance, represented in Fig. 5 by the reference character CZ, and consequently giving a small upward motion tothe needle,

Fig. 6, before the looper 16 begins its advancing stroke. .Regarded from another viewpoint, as the lower end of the pitman ll is swung to the left from full to dotted line position, Fig. 5, the entire pitman is lowered slightly, rcpresented'by the distance (Z. rlhe motion of the pitrnan to the left, however, shifts a higher portion pf the guideway 27 into engagement .with the follower 223, thus compensating for the drop of the pitman. .The slight upward motion ofthe needle thus obtained, while the looper dwells, gives the needle an opportunityto throw out a loop a size suiiicicnt for certain seizure by the looper 1,6, the point Vof which it will be noted lies close to the needle in Fig. 6l Y When the looper reaches the position in Fig. -l, the lint: A19 alines itself with the arm 20, Fig. 3, and thus acts as a toggle, causing the looper to dwell fora time which isprolonged by the endwise motion of the guideway e? at this period of the cycleflt will be observed that during the latter portion of the uprstrolre of the pitman l1, the upward motion imparted to the follower 23 is accelerated by the inclined guideway 27 whichmoves awayfrom the fulcrum 22 and ferret l`upperm'ost position shown mlFiggwT-he ,ly fprior vto*"reaching the.Y ent-reine ksaid looper-carrier.

operating linkage and not through a second crank or eccentric on the main-shaft. The careful relative timing or adjusting of two eccentrics on the main-shaft is therefore not required to time the loop-taker to the needle.

The invention is vnot to be understood as limited to chain-stitch machines as it is obviously applicable to any sewing machine having a to-and-fro moving loop-taker.

Having thus set forth the nature of the invention, what l claim herein is l. ln a sewing machine, a reciprocating needlma loop-er Vhaving loop-seizing and loop-shedding movements, a main-shaft, an eccentric on said shaft, a Vmember actuated by said eccentric, actuating connections between said member and said needle and loop-taker` said connections including means for delaying the beginning of the loop-seizing movementof the looper relative to the rising movement of the needle until the needle has risen a short distance from the lower limit of its stroke.

2. In a sewing machine, a. needle, a needlecarrier, a loop-taker, a mainshaft, an eccentric on said shaft, a connection including a pitman embracing said eccentric for operating said needle-carrier, and an operative connection between said loop-taker and said pitman intermediate the ends of the latter',

said last mentioned connection including guideway and follower elements one of which is carried by said pitman and the other connected to said loop-taker.

3. Ina chain-stitch sewing machine, a needle, a rotary7 driving shaft, an eccentric on said shaft, a pitman embracing said eccentric and connected to reciprocate said needle, said pit-man being formed with a transverse guideway which is turned away from a line normal to the longitudinal axis of said pitman in the direction of rotation of said driving shaft, a looper, an oscillatory looper-carrier, and a follower embraced by said Aguideway and connected to oscillatehln a sewing.machine,aneedlda rot-ary driving shaft, an eccentric on Asaid shaft, a pitnianembracing said eccentric and connected to', reciprocate said needle, said pitman being formed with a transverse Vguideway, anw oscillatory loop-taker, and a follower embracedby said .guideway and con'- nected to oscillate saidlooptaker. said follower beingin the Aformjcf la lever fulcrnmed 'at a level 'between'thelevels of the upper 1,e11,sse

and lower extreme positions of the guideway.

In a chain-stitch sewing machine, a needle7 a rotary driving shaft, an eccentric on said shaft, a pitlnan embracing said eccentric and connect-ed to reciprocate said needleE said pitman being formed with a transverse guideway which is turned away from a line normal to the longitudinal axis of said pitman in the direction of rotation of said driving` shaft, a looper, an oscillatory looper-carrier, a follower embraced by said guideway and connected to oscillate said looper-carrier, said follower being in the 'form of a lever ulcrumed at a level between the levels of the upper and lower extreme positions oiI the guideway, and the connections between said follower and looper including a toggle device causing the looper to have a prolonged dwell at the end of its loop-seizing stroke.

6. In a vsewing machine, a reciprocating needle, a to-and-fro moving looper7 a looperactuating eccentric, a pitman connected to said eccentric and having a guideway which is turned away from a line normal to the longitudinal aXis of the pitman in the direction of rotation of said eccentric, and a follower embraced by said guideway and connectedto actuate said looper.

7. In a sewing machine, a reciprocating needle, ato-and-fro moving looper, a looperactuating eccentric, a pitman connected to said eccentric and having a guideway which is turned away from a line normal to the longitudinal axis of the pitman in the direction of rotation of said eccentric and a pivoted follower lever actuated by said guideway and connected to actuate said looper.

In testimony whereof, I have signed my name to this specification.

ANDREW B. CLAYTON. 

